Trimming mechanism for sewing-machines.



J. R. MOFFATTf TRIMMING MECHANISM FOR SEWING MACHINES. APPLICATION FILEDJUNE 7, I9l2.

1,230,753. I Patented June 19, 1917.

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TRIMMING MECHANISM FOR SEWING MACHINES. v

. APPLICATION FILED JUNE 1, I912- I 1 ,230,753. Patented June 19, 1917.

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J. R. MOFFATT.

TRIMMING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED JUNE 1. I912.

1,230,753. Patented June 19, 1917.

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IRIMMING MECHANISM FOR SEWING MACHINES.

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MOFFATT,

TRIMMING MECHANISM FOR SEWING MACHINES. APPLICATION FILED JUNE 1. i912.

1,230,753. Patented June 19, 1917.

5 SHEETS-SHEET 5.

- UNITED STATES PATENT @FFICE.

JAMES R. MOFFATT, OF CHICAGO, ILLINOIS, ASSIGNQR TO UNION SPECIALMACHINE COMPANY, OF CHICAGO, ILLINOIS, ACORPORATION OF NEW YORK.

TRIMMING MECHANISM FOR. SEWING-MACHINES.

Specification of Letters Patent.

Patented June 19, 1917.

App1ication filed June 7, 1912. Serial No. 702,242.

nois, have invented certain new and useful Improvements in TrlmmingMechanlsms for Sewing-Machines, of which the following is a description,reference being hadto the accompanying drawing and to the figures oflifting the presser foot;

reference marked thereon The invention relates to new and usefulimprovements in sewing machines, and more especially to a trimmingmechanism which is adapted to trim the fabric in advance of thestitching mechanism An object of the invention is to provide a trimmingmechanism wherein the movable blade is suspended above the work support,and is operated by devices connected with the main shaft beneath thework support, whereby the support for the movable trimmer blade may bepositioned well above the work support to give plentyof room underneaththe same, and also to afford suflicient length of lever-operating roomfor the trimmer, so that the proper force for operating the same may beobtained.

A further object of the invention consists in providing a trimmingmechanism of the above character with devices whereby the movabletrimming blade may be disconnected from its operating mechanism and heldraised from operative relation to the stationary trimming member.

These and other objects will in part be obvious, and will in part behereinafter more fully disclosed.

In the drawings which show by way of illustration one embodiment of theinvention,-

Figure 1 is a rear view of a sewing machine having my invention appliedthereto;

Fig. Qis an end view of the same;

Fig. 3 is a plan and horizontal sectional view taken at a point abovethe trimming mechanism;

Fig. 4 is a perspective view of the upper trimming mechanism;

Fig. 5 is a perspective view of the rocking member for operating themovable trimmer blade;

Fig. 6 is a perspective view, showing the arm for carrying the trimmerblade, the trimmer blade and the clamp being sepa rated for the sake ofclearness;

by a supporting arm 13. mounted in a projecting lug 15, formed in- Fig.7 is a perspective view of the presser foot and the strip-depressingfinger, these parts being separated for the sake of clear ness;

Fig. 8 is a vertical sectional View showing the trimmer-operatingmechanism in side elevation, and its relation to the stitching mechanismFig. 9 is a. side view of a foot treadle for Fig. 10 is a detail showingthe spring for holding the trimmer blades in contact; and

Fig. 11 is an enlarged detail, showing the locking lug for holding thetrimmer raised;

Fig, 12 is a detail in section, showing the abutment collar for themovable trimming member.

In carrying out the invention, I have provided a sewing machine whichconsists of a bed plate 1, from which rises a standard '2, carrying anoverhanging arm 3. A needle bar 4 reciprocates in the forward end of theoverhanging arm, and carries a needle 5. The machine as herein shown, ispref- -erably used for binding the cut edge of a fabric, and anysuitable complemental stitch-forming devices may be used with theneedle. It will be understood from certain aspects of the invention,however, that other types of stitching mechanism may be employed.

The material is fed to the needle by a feed dog 6, which is given theusual four motions. Cooperating with the feed dog 6 is a presser foot 7.The bed plate is provided with standards, on which is mounted a worksupport 8. The work supp0rt 8 carries a trimmer support 9, in which thestationary trimming blade 10 is mounted. A movable trimming blade 11cooperates with the stationary trimming blade. These blades, as clearlyshown in Fig. 8, are disposed in front of the stitching mechanism.

This machine, as above noted, is especially designed for trimming andcovering a cut edge with a binding strip. The trimming mechanism,therefore, is located at some distance in advance of the stitchingmechanism, so that a binder 12 may be used forguiding a binding stripand placing the same around the cut edge after it is operated upon bythe trimming mechanism,

The movable trimmer blade 11 is carried A shaft 14 is tegral with thestandard 2 of 'the machine, and in a bearing 16 carried by a bracket 17,which is secured to the overhanging arm adjacent the needle head. Saidbracket 17 1s secured by the screws 18 to the overhangmg arm. This shaft14 is loosely journaled 1n the supporting ing or bearing-15 and thebearing 16. The trimmer-supporting arm 13 is clamped to the shaft 14 byscrews 19 through the intermediary of a split sleeve collar 48, so thatthe oscillations of the arm 13 and the lateral movements thereof, willbe impartedto the shaft 14.

The trimmer-operating member 20, as hereinshown, is in the form of arock lever which;has an arm 21 adapted to be secured to thetrimmer-supporting arm, and an arm 22 which is adapted to be connectedto the operating mechanism on the main shaft. This trimmer-operatingmember 20 is loosely journaled on the shaft 14. Said member is locatedadjacent the supporting collar for the arm 13, and a collar 23 which isfixed on the shaft '14.

The forward end of the arm 21 is forked as at 24. The supporting arm 13for the trimmer has a laterally projecting car 25, which extends overthe forked end of the arm 21. A short vertical shaft 26 is supported bythe ear 25, and this shaft is turned by a handle 27 which is rigidlysecured thereto. The lower end ofthe shaft 26 is formed with arectangular securing head 28. The forked end 24 of the arm 21 is soproportioned that when the rectangular head 28 extends lengthwise of thearm 21, said head will pass between the arms of the fork, but when saidhead is turned at right angles to the plane of the arm 21, said headwill then engage the under faces of the forks and securely hold the arm13 to the operatingarm 21 of the rocking member for the upper movabletrimmer blade.

The movable trimmer blade 11, as herein shown, is curved, and is securedto thearm 13 by a retaining clamp 29, which is held on the arm by ascrew 30.

The arm 22 has .a stud 31 at its lowerend which is engaged by aneccentric strap 32, The eccentric strap 32 cotiperates with an eccentric33 mounted on the main shaft 34. This main shaft 34, the eccentric 33and the strap 32 are all disposed beneath the plane of the work support.As the shaft rotates, the eccentric will oscillate the arm 22, whichwill in turn vibrate the movable trimmer blade.

The shaft 14, as above noted, is freely mounted in its supportingbearings. A sleeve 35 surrounds said shaft and is clamped theretoby ascrew 36. A portion of said sleeve is bored out so as to receive aspring 37. This spring bears at one end against the end of the sleeve,and at its other end against a loose collar 38, which is carried by oneof these ribs.

rests against the bearing 15 for the shaft 14. This spring normallypresses the shaft 14 longitudinally in a direction so as to hold themovable trimmer blade in contact wlth the stationary trimmer blade.

'On the end of the shaft 14 is an arm 39. The standard 2 is formed ateach side there of with projecting ribs, and the bearing 15 The shaft14, therefore, projecting through the hearing and rib is exposed so thatthe arm 39 may be'mounted thereon and have a limited swinging mo'tionrelative to the standard. A lug 40 is secured to the standard 2, and isprovided with a rib 41, adapted to en gageya groove 42 formed .in thelower end of the arm 39.

When the trimmer-supporting member 13 is disconnected from the operatingrocker member 20, it may be raised and as the movable trimmer blade israised, the shaft 14 will beoscillated, which will bring the arm 39 intocontact with the lug 40 and the rib 41 will engagethe groove 42, andthus hold the trimmer blade in raised position. The spring 37 will allowthe shaftto yield, so that the groove may engage the rib.

The bracket 17 which supports the outer end ofthe shaft 14 is providedwith an oil guard 43, which extends underneath the bearing '16, andserves as ameans for catching anyoil dripping from the bearing anddirects the same to one side of the work support on which the materialbeing stitched lies.

Thepresser foot 7 .is carried by a presser bar 44 and said presser baris raised and lowered by a lever 45 to which is attached a'rod 46. Theopposite end of the rod 46 is attached to a foot treadle 47.

In the operation of my device,.the rotating 7 through the binder 12, andthe binding strip will be stitched to the material.

VVhenit isdesired to render the trimmer inoperative,.the supporting arm13 therefor is disconnected from the vibrating arm 21, and said arm 13is raised, which will throw the arm 39 into locking engagement with therib on the lug .40, and thus the upper trimming blade will. beheld ininoperativeposi tion.

It will be noted from the above description, that I have provided atrimming mechanism wherein thesupport for the operating lever is carriedby the overhanging arm, and

from the rear of the machine to the binder.

The arrangement of the binder and the parts of the trimming mechanismrelative to the stitching mechanism, form no part of the presentinvention, but are shown, described and claimed in my co-pendingapplication filed of even date herewith Serial No. 702,243.

There is one other feature in connection with my machine, which is ofconsiderable importance in connection with trimming clevices, moreparticularly wherein a movable blade cooperates with a fixed blade tosecure a shearing cutting action. In devices of this character asheretofore constructed, it has been customary to provide a spring forforcing the movable blade toward the stationary blade to hold saidblades in proper cooperative action. In order that the blades may bepressed into contact with a sufficient force to shear the fabric, thespring is necessarily of considerable tension, which'causes excessivewear between the contacting parts of the trimmer, and especially theguidingfinger or point of the trimming blade. I have provided meanswhereby the proper spring pressure may be employed, and the unduepressure between the blades, avoided.

This means, as herein illustrated, consists of a collar 48 which isthreaded into the arm 13 carrying the movable blade. The hub of the arm13 is cut-away and threaded to receive the collar. The screws 19 areloosened and the collar can be adjusted in and out of the arm, afterwhich the screws are turned up to firmly hold the collar in adjustedpositions. This collar is adapted to engage the bearing 16 of thebracket 17. In the setting of my trimmer, the two blades are broughtinto contact, and the tension of the spring 37 adjusted by shifting thesleeve 35 until the blades will form a proper shearing action on a thinpiece of material, such as tissue paper, after which the collar isadjusted until it bears against the arm 16, when it is locked bytightening the screws 19. This collar relieves the knives of theexcessive spring pressure as the force of the endthrust of the shaft14-, will be taken up by the bearing 16 and the collar 48, The collar4:8 is a split collar and is threaded into the arm 18. lVhen the screws19 are turned, the arm 13 and collar 48 will be firmly clamped to theshaft 14. so that the shaft turns with this arm and also moves endwisetherewith.

The collar 48 will then take the end-thrust of the shaft 14, and yetpermit the movable blade to be spring-pressed toward the stationaryblade with sufficient force to secure a proper shearing action. In otherwords, I have provided a mechanical device to receive the pressure ofthe spring, so that the pressure is taken away from the cutting edge,which would have the eflect of springing the knives and which would alsocause the knives to wearout at their frictional or contacting point.

It is obvious that minor changes in the details of construction may bemade, without departing from the spirit of the invention as set forth inthe appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is

1. A trimming mechanism including in combination, a bed plate, a worksupport, a standard carried by the bed plate, an overhanging arm mountedon the standard, a shaft, bearings carried by the standard and theoverhanging arm, a trimmer blade, an arm attached to said shaft forsupporting said blade, :1 member loose on said shaft, means forvibrating said member, and means for connecting and disconnecting saidmember to the arm supporting the trimmer blade and at a point adjacentsaid blade.

2. A trimming mechanism including in combination, a bed plate, a worksupport, a standard carried by the bed plate, an overhanging arm mountedon the standard, a shaft, bearings carried by the stand ard and theoverhanging arm, a trimmersupporting arm carried by said shaft, atrimmer blade supported by said arm, a rocking member having an armadapted to be detachably connected with the trimmersupporting arm, anarm extending beneath the work support, means connected with said armbeneath said work support for vibrating said rocking member, and meansfor yieldingly moving said shaft longitudinally, an arm mounted on theend of the shaft, and a locking lug for engaging said arm to hold saidtrimmer blade in raised position when disconnected from the rockingmember.

3. A trimming mechanism including in combination, a bed plate, a worksupport, a standard carried by the bed plate, an overhanging arm mountedon the standard, a shaft, bearings carried by the standard and theoverhanging arm for supporting said shaft, a trimmer-supporting armcarried by said shaft, a trimmer blade mounted on said arm, a stationarytrimmer blade cooperating therewith, a rocking member loosely mounted onsaid shaft and having an arm adapted to be detachably connected with thesupporting arm for the trimming member adjacent said trimming member,said rocking member having a second arm extending beneath the worksupport, a

main shaft beneath the Work support, an eccentric carried thereby, and astrap cooperatin with said eccentric and connected to said arm extendingbeneath the Work support.

i. A trimming mechanism including in combination, a bed plate, a worksupport, a standard carried by the bed plate, an overhanging arm mountedon the standard, a shaft, bearings carried by the standard and the.overhanging arm for supporting said shaft, a trimmer-supporting arm carried by said shaft, a trimmer blade mounted on said arm, a stationarytrimmer blade cooperating therewith, a rocking member loosely mounted onsaid shaft and having an arm adapted to be detachably connected with thesupporting arm for the trimming member, said rocking member having asecond arm extending beneath the work support, a main shaft beneath theWork support, an eccentric carried thereby, a strap cooperating withsaid eccentric and connected to said arm extending beneath the worksupport, and a spring for moving said shaft endwise for yieldinglyholding the trimmer blades in contact.

5. A trimming mechanism including in combination, a bed plate, a worksupport, a standard carried by the bed plate, an overhanging arm mountedon the standard, a shaft, bearings carried by the standard and theoverhanging arm for supporting said shaft, a trimmer-supporting armcarried by said shaft, a trimmer blade mounted on said arm, a stationarytrimmer blade cooperating therewith, a rocking member loosely mounted onsaid shaft and having an arm adapted to be detachably connect- 1,2so,753t ed with the supporting arm for the trimming member, said rockingmember having a second arm extending beneath the Work support, a mainshaft beneath the work support, an eccentric carried thereby, Y

a strap cooperating with said eccentric and connected toisaid armextending beneath the Work support, a spring for moving said shaftendwise for yieldingly holding the trimmer blades in contact, an armcarried by the end of said shaft, and a locking lug cooperating withsaid arm for holding the trimmer in raised position when disconnectedfrom its actuating mechanism.

6. A trimming mechanism including in combination a stationary blade, amovable blade, a spring for forcing the movable blade against thestationary blade and a member adjustable relative to the stationaryblade for limiting the thrust of the JAMES R. MOFFATT. Witnesses G.McNnIL, A. B. OLOTHIER.

Copies ofthis patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, I). C.

